Formation of Kondo Lattice in La_1-<i>x</i>Ce_<i>x</i>Ni

Abstract

Temperature dependences of the resistivity and the susceptibility of single crystals of solid solution La 1- x Ce x Ni have been measured in the temperature range 2–300 K. We have obtained a phase diagram of La 1- x Ce x Ni which is consisted of three parts; (1) isolated Kondo region ( x <0.6 and whole temperature region), where each 4f electron is in a localized trivalent state, (2) fairly isolated dense Kondo region ( x >0.6 and high temperature region), where the 4f electron behaves as fairly localized electron although the valence of the Ce ion is more than three and (3) Kondo lattice region ( x >0.6 and low temperature region), where the 4f state becomes a delocalized state.